Polyphenyl ether compositions useful as functional fluids



United States Patent 3,290,247 POLYPHENYL ETHER COMPOSITIONS USEFUL AS FUNCTIONAL FLUIDS Glenn R. Wilson, Cambridge, and John R. Stemniski,

Swampscott, Mass., and Kenneth L. McHugh, Kirkwood, Mo., assignors to Monsanto Research Corporation, St. Louis, Mo., a corporation of Delaware N0 Drawing. Filed May 14, 1962, Ser. No. 194,650

18 Claims. (Cl. 252--42.7)

This invention relates to liquid fluids of high thermal stability and more particularly provides functional fluids comprising polyphenyl ethers and certain organic compounds of tin as adjuvants therefor.

The polyphenyl ethers are known compounds which have found wide application as functional fluids owing to their very good thermal stability, resistance to foam, and lubricity. For example, they have been found to be valuable as hydraulic fluids, as heat-exchange media, as atomic reactor coolants, as diffusion pump fluids, as lubricants in motor operation generally, and particularly as jet engine lubricants.

With recent changes in the design of aircraft engines, there is a demand for lubricants which will perform satisfactorily under conditions far more rigorous than ever contemplated in the past. A particularly important requirement for lubricants intended for use in the newly designed engines is that their viscosity and lubricity be unaffected by the high temperatures to which they are necessarily subjected.

As is known in the art, petroleum lubricants generally comprise, in addition to the petroleum base stock, additives or adjuvants which impart specifically desired properties to the base stock, e.g., rust-inhibitors, anitioxidants, extreme pressure-resisting agent, lubricity improvers, detersives, etc. The additives proposed heretofore have been designed to accommodate the requirements of petroleum base stocks for lubrication in conventional equipment such as internal combustion engines of the automotive type, diesel engines and the like. One feature in common with respect to these various applications was that the temperature of use was not excessive, i.e., it may vary from about 40 F. to 400 F. With the advent of extremely high speed aircraft of the jet type, it was found that neither the petroleum base stock nor the conventional additives used therewith were practical, because the lubricant and the additives had to be effective at temperatures which were above the decomposition points of the known compositions, e.g., at temperatures which were generally within the range of 500 F. to 700 F. It was also found that when conventional additives were employed with functional fluids having higher thermal stability than that possessed by petroleum base stocks, the additives did not perform in a predictable manner, i.e., a material possessing antioxidant effect or an extreme pressure-resisting effect with the petroleum hydrocarbon lubricants generally did not possess such effects when used with the polyphenyl ether fluids.

Although the polyphenyl ethers possess extremely good thermal stability, at temperatures of, say, over 550 F., they tend to deteriorate, not because of a decomposition reaction, but because at the higher temperatures they become quite readily oxidizable. The lubricity of the polyphenyl ethers is thereby impaired, since the oxidation products do not possess lubricating properties; moreover, the change in viscosity which is a consequence of the oxidation not only makes for inetficiency, but also may clog up the moving parts of the mechanism which the lubricant was originally intended to protect. Hence, when the polyphenyl ethers are to be used at the higher temperatures under conditions requiring exposure to air, it is necessary 3,290,247 Patented Dec. 6, 1966 to inhibit oxidation phenomena which the higher temperatures favor.

The polyphenyl ethers, like conventional petroelum lubricants, are also somewhat deficient with respect to lubricity, anti-wear and extreme pressure-resisting properties, e.g., breakdown of lubricant film occurs under some conditions of use, particularly at the extreme pressures encountered in gear lubrication. Here again, conventional lubricity, anti-wear and extreme pressure-resisting (E.P.) additives are generally ineifective with the polyphenyl ethers and do not withstand the very high temperatures at which the high thermal stability of the ethers could make them of most use. W V 7 Accordingly, an object of the present invention is the provision of improved polyphenyl ether fluid compositions. Another object of the invention is the provision of polyphenyl ether compositions having improved antioxidant properties. Still another object of the invention is the provision of polyphenyl ether compositions having improved lubricity. A further object is the provision of polyphenyl ether compositions having improved anti-wear properties. Still a further object is the provision of polyphenyl ether compositions having improved extreme pressure-resisting properties. A most important object of the invention is the provision of polyphenyl ether compositions which possess an improved resistance to oxidation at temperatures of over 560 F.

These and other objects hereinafter disclosed are provided by the invention wherein there is employed as additive for the polyphenyl ether liquid fluids an organic compound of tetravalent tin wherein the tin is linked through a chalcogen element having an atomic weight of less than 33 to a carbon atom or another tin atom of the rest of the molecule. Particularly valuable are compounds selected from the class consisting of those having the formula where n is a number of from 2 to 3, m is a number of 1 to 2 and the total of m+n is 4, R is selected from the class consisting of alkyl radicals of from 1 to 12 carbon atoms, benzenoid hydrocarbon radicals which are free of olefinic and acetylenic unsaturation and contain from 6 to 12 carbon atoms, and aryloxyaryl radicals of from 12 to 24 carbon atoms, and such radicals carrying halogen substitution; R is selected from the class consisting of R, paraffinic and haloparaflinic acyl radicals of from 2 to 12 carbon atoms, the radical wherein Z denotes the necessary members to complete a saturated heterocyclic radical of from 6 to 10 members, the radicals -SnR and -ary1eneOSnR and X is a chalcogen element having an atomic weight of less than 33; and those having the formula Lil.

where Y is selected from the class consisting of arylene radicals of from 6 to 12 carbon atoms, arylenealkylenearylene radicals and alkylene-arylenealkylene radicals having from 1 to 4 carbon atoms in the alkylene radical and from 6 to 12 carbon atoms in the arylene radical, R and X are as above defined, and y is a number denoting the degree of polymerization.

Compounds having the formula R Sn(XR) are derivatives of tin hydroxides or thiols. When R is R,

and X is oxygen, the compounds are hydrocarbonoxytin .Or h'ydrocarbonoxyhydrocarbontin compounds or halogen derivatives thereof, i.e., they have the formula:

The corresponding thio compounds have the formula: R SnSR Rz t mz Examples of C are ben'zylthiotripropyltin, decylthiotriphenyltin, iodophenylthiotrimethyltin, heptylthiotris(ptolyloxyphenyDtin, tributylphenylthiotin and tri-pentyl-p-- biphenylylthiotin. Examples of D are dibutylbis(buty1 thio tin, diphenyl'bis (phenylthion )tin, diphentylbis benzylthio) tin, bis p-phenoxyphenyl) bis (p-phenoxyphenoxy) tin, etc.

When R' is an acyl radical, the presently useful compounds are esters of parafiinic or haloparafiinic acids. Depending upon whether they are mono-esters or di-esters and upon whether they are O-esters or S-esters, the com pounds have the formula:

:wherein R" is selected from the class consisting of tate, tris(p-tolyl)tin 3-fluorothiopropionate, and tripentyltin thiodecanoate. Y

Compounds of the Formula G include dihydrocarbontin or bis(hydrocarbonoxyhydrocarbon)tin alkanoates, e.g., diphenyltin dihexoate, dibutyltin dinonoate, bis'( 4-phenoxyphenyl)tin or dixylyltin dipropionate. Particularly valuable for the present purpose are the hitherto unknown diaryltin bis(haloalkanoates) having from 6 to 12 carbon atoms in each aryl group and from 1 to carbon atoms in each haloalkanoate group, e.g., diphenyltin bis(2-fluoropropionate), di-p-tolyltin bis(tetra'bromobutyrate), di-u-naphthyltin bis(iodoacetate), (bis pbiphenylyDt-in bis(trichloroacetate), diphenyltin bis(chlorovaler-ate) etc. They are readily prepared by the reaction of a dihydrocarbontin dihalide with a haloalkanoic-acid substantially according'to the scheme where hydro denotes a 'benzenoid hydrocarbon radical, X is halogen and Z is a halogen-substituted alkyl radical of from 1 to 5 carbon atoms.

Examples of compounds of the Formula H are diphenyltin bis(thiopropionate), di a-naphthyltin bis(thiochl0- roacetate) or dipentyltin bis'(t-hiolaurate).

When R is the nitrogenous heterocyclic radical, the presently useful compounds have the formula Illustrative of I where X is sulfur is (Z-benzothiazolylthio)tri-b utyltin, and illustrative of I Where X is oxygen is bis(S-quinolyloxy)di-o-tolyltin.

The presently useful compounds may also be organic tin oxides or sulfides, i.e., compounds of the formula:

As examples of presently useful oxides or sulfides of the above formula may be mentioned:

Bis(tributyltin) oxide, Bis(tripentyltin) sulfide, Bis[tris(2-fluoroethyl)tin] oxide, Bis(trihexyltin) oxide, Bis,triisob utyltin) oxide, Bis(tribenzyltin) sulfide, Bis(tricyclohexyltin) oxide, Bis(tri-o-tolyltin) oxide, Bis(t-riphenyltin) oxide, Bis(tri- 3-naphthyltin) sulfide, Tributyltin triphenyltin oxide, Methyldiethyltin trioctyltin oxide.

Particularly valuable for the present purpose are the bis[=(halophenoxy)dihydrocarbontin] oxides. They may be readily prepared by the reaction of a dihydrocarbontin oxide with a halophenol, as described in the copending application of Glenn R. Wilson, Serial No. 194,643, filed of even date and now US. Patent No. 3,213,119. The reaction proceeds substantially as follows:

I l O O l where X is halogen, hydro is selected from the class consisting of alkyl, aryl, alkaryl and aralkyl radicals of from 1 to 12 carbon atoms and n is a number of from 1 t0 5. Examples of such compounds are bis'[(0-, mor p-chlorophenoxy)diphen-yltin] oxide which is prepared from 0-, mor p-chlorophenol and diphenyltin oxide; 'bis [-(pentachlorophenoxy) dimethyltin] oxide which is prepared from pentachlorophenol and dimethyltin oxide; bis (2,3-dibromophenoxy) dibenzyltin] oxide which is prepared from 2,3-di'bromophenol and dibenzyltin oxide; bis ['(o-, mor p-fiuorophenoxy) dipentyltin] oxide which is prepared from o-, mor p-fluorophenol and dipentyltin oxide; =bis[2-chloro-3-iodophenoxy)di p tolyltin] oxide Which is prepared from 2-chloro-3-iodophenol and p-tolyl- 'tional fluids are compounds in which two stannoxy groups are separated by an arylene group, i.e., compound of the formula:

where the arylene group contains from 6 to 1Q carbon atoms, e.g., phenylene, biphenylylene, naphthylene, tolylylene, sylylene, etc., and R is alkyl, aryl or aryloxyaryl. Compounds where R is aromatic hydrocarbon are preferred and numerous such compounds are disclosed in the copending application of Glenn R. Wilson, Serial No. 194,644, filed of even date, and now abandoned. In the above formula, when the arylene group is phenylene, the useful compounds are derivatives of hydroquinone, catechol or resorcinol. The products, which are bis(trihydrocarbonstannoxy)benzenes, are readily obtained by reaction of the appropriate trihydrocarbontin halide with the dihydroxybenzene compound, thus HO OH (hydro);-S r-O For example, reaction of hydroquinone with trirnethyltin bromide gives p-bis(trimethylstannoxy)benzene; reaction of pyrocatechol with tribenzyltin chloride gives o-bis(tribenzylstannoxy)benzene; reaction of resorcinol with tri-o-, mor p-tolyltin gives m-bis(tri-o-, mor p-tolylstannoxy)- benzene; reaction of hydroquinone with dibutyldodecyltin iodide gives p-bis(dibutyldodecylstannoxy)benzene; reaction of resorcinol with tIi-aor ,B-naphthyltin gives rn-bis- (tri-aor fl-naphthylstannoxy)benzene, etc.

Of interest also, particularly as antioxidants, are polymeric organic tin oxides or sulfides, e.g., such as those described in the copending application of Glenn R. Wilson, Serial No. 194,642, filed of even date and now US. Patent No. 3,184,430. Generally, the presently useful organotin polymers consist essentially of the repeating unit:

where Y is arylene of from 6 to 12 carbon atoms or alkylenearylenealkylene where arylene has from 6 to 12 carbon atoms and alkylene has from 1 to 4 carbon atoms, X is oxygen or sulfur and R is an alkyl radical or a saturated benzenoid hydrocarbon radical or such a radical carrying halogen substitution or an aryloxyaryl radical. The number of such units in the polymeric product will vary, but will generally be from, say, to 1000. The polymers are oxygen and/ or sulfur ethers. Thus, when Y is phenylene and X is oxygen, the polymers consist of the oxygen ether unit A polymer of the above formula wherein R is an alkyl radical has the phenyleneoxydialkyltinoxy unit, and is readily obtained by reaction of a dihydroxybenzene, i.e., hydroquinone, catechol or resorcinol, and a dialkyltin dihalide. Presently useful polymers of the above formula having thio linkages instead of oxygen linkages are obtained by using a dithiol instead of the dihydroxybenzene compound. Polymers having both oxygen and sulfur linkages are also presently useful. These are obtained by employing mercaptophenols instead of the dihydroxy compounds or the dithiols. Although, because of the easy availability of the benzene compounds, the dihydroxyphenols, the benzenedithiols or the mercaptophenols are the generally used starting materials, the arylene group need not be the phenylene group. Instead, it may be the biphenylylene group derived, e.g., by using dihydroxybiphenyl with the diorganotin dihalide; or it may be the naphthylene group, the fluorenylene group, the acenaphthylene group, etc. Also, the bivalent aromatic nucleus may or may not carry one or more alkyl or cycloalkyl substituents, e.g., it may be the cyclopentylphenylene, the

tretramethylphenylene or the ethylnaphthylene group. When Y in the repeating unit of the presently useful organotin polymer is alkylenearylenealkylene, the polymers are derived generally from the arenebis(alkanols) or the arenebis(alkanethiols), e.g., 0-, mor p-xylene-a,et'-diol, durene-a,a'-diol, o-, mor p-benzenediethanol, o-, mor p benzenebis(ethanethiol), p xylene-m-ol-d-thiol, 1,4- naphthalenedirnethanol, 4,4'-biphenyldiethanol, etc. For example, reaction of p-xylene-u,u'-diol and diphenyltin chloride gives a presently useful polymer having the repeating unit Polymers having two oxygen and/ or sulfur linkages C Ha C 2H5 Many of the presently useful organotin compounds are generally prepared by reaction of a diorganotin dihalide or of a triorganotin trihalide with an organic compound containing at least one hydroxy, thiol, carboxy, or thiocarboxy group, with evolution of hydrogen halide. Others are prepared by reaction of a dihydrocarbontin oxide and hydroxy compounds or thiols with evolution of water. Depending upon the nature of the individual reactants, the reaction may be effected by simply contacting the two reactants in the presence or absence of a solvent or diluent at ordinary or increased temperatures. Generally, when a diluent is employed, reaction is conducted at the refiuxing temperature of the mixture in order thereby to minimize reaction time. Also, although catalysts are not generally necessary, reaction may sometimes be accelerated by the use of a catalytic quantity of a basic agent, e.g., an alkali metal hydroxide or a basic salt or alcoholate thereof, a quaternary ammonium compound, etc. In many instances, use of catalyst is dispensed with by working with alkali metal or ammonium salts of the hydroxy compounds or thiols rather than with the free alcohols, phenols or thiols. When operating with large quantities of halides as the organotin reactant, it may be advantageous to provide for removal of the evolved hydrogen chloride. This may be done by vigorous stirring, dephlegmation or by use of a hydrogen chloride scavenger. When working with oxides as the organotin reactants, use of a diluent which forms an azeotrope with water is recommended. Advantagcously, the organotin halogen compound and the hydroxy, thio or carboxy compound are used in stoichiometric proportions. However, an excess of either reactant may be employed, since unreacted material is readily recovered from the final product.

The polyphenyl ethers to which this invention pertains have from 4 to 7 benzene rings and from 3 to 6 oxygen atoms. They can be represented by the structure where n is a whole number from 2 to 5. The preferred polyphenyl ethers are those having all their ether linkages in the meta position since the all-metal linked ethers are the best suited for many applications because of their wide liquid range and high degree of thermal stability. However, mixtures of the polyp-henyl ethers, i.e., either isomeric mixtures or mixtures of homologous ethers, can also be used to obtain certain properties, e.g., lower solidification points. Examples of the polyphenyl ethers contemplated are the bis(phenoxyphenyl) ethers, e.g., bis(m-phen-oxyphenyl) ether, the -bis(phenoxyphenoxy) benzenes, e.g., m bis(m-phenoxyphenoxy)benzene, mbis (p phenoxyphenoxy)benzene, o bis(o phenoxyphenoxy)benzene, the bis(phenoxyphenoxyphenyl) ethers, e.g., bis[m-(m-iphenoxyphenoxy)phenyl] ether, bis[p-(pphenoxyphenoxy) phenyl] ether, m [m phenoxyphenoxy) (o-phenoxyphenyl)] ether and the his (phenoxyphenoxyphenoxy)benzenes, e.g., m-bis[m-(m phenoxyphenoxy)phenoxy]benzene, p-bis[p-('m phenoxyphenoxy)- phenoxy]benzene, m bis[m-(p-phenoxyphenoxy)phenoxy]benzene. It is also contemplated that mixtures of the polyphenyl ethers can be used. For example, mixtures of polyphenyl ethers in which the non-terminal phenylene rings (i.e., those rings enclosed in the brackets in the above structural representation of the polyphenyl ethers contemplated) are linked through oxygen atoms in the media and para positions, have been found to be particularly suitable as lubricants because such mixtures possess low solidification points and thus .provide compositions having wider liquid ranges. Of the mixtures having only meta and para linkages, a preferred polyphenyl ether mixture of this invention is the mixture of -.ring polyphenyl ethers where the non-terminal phenylene rings are linked through oxygen atoms in the meta and para position and composed, by weight, of about 65% m-bis(m-phenoxyphenoxylbenzene, 30% m-[(m-phenoxyphenoxy) (p-phenoxyphenoxy)]benz ene and 5% m bis(p phenoxyphenoxy)benzene. Such a mixture solidifies at about 10 F., whereas the three components solidify individually at temperatures above normal room temperatures.

The aforesaid polyphenyl ethers can be obtained by the Ullmann ether synthesis which broadly relates to ether forming reactions, e.g., alkali metal phenoxides such as sodium and potassium phenoxides are reacted with aromatic halides such as bromobenzene in the presence of a copper catalyst such as metallic copper, copper hydroxides, or copper salts.

The present oxygenated organic tin compounds are combined with the fluid polyphenyl ethers to the extent of 0.1% to 10.0% by weight depending upon the nature of the tin compound and of the ether fluid and upon the 'adjuvant effect desired. The tin compounds generally have a beneficial effect on the polyphenyl ether in that there is obtained improvement in stability to oxidation and/or increased lubricity and/or increased resistance to wear and extreme pressure. All of these benefits do not necessarily result from the use of one additive, although a number of the tin compounds do confer a plurality of such effects when employed with the ethers within the above-stated range of concentration. Whether or not a desired adjuvant effect is obtained is readily determined by use of conventional testing procedures known to those skilled in the :art. The effectiveness of the present tin compound additive is also not the same over the entire range of concentration; for example, while it has been noted that in most cases the ability of the agent with respect to anti-wear and extreme pressure lubrication improves markedly -as the concentration is increased, the reverse may be true insofar as antioxidant effect is conoerned, lower amounts of the additive often resulting in a greater degree of stability to oxidation at the high temperatures than that attained by use of the greater amounts of the same additive.

Testing of the adjuvant eflects of the oxygenated organic tin compounds when employed with the pol enyl ether fluid was conducted as follows: i

The anti-wear and extreme pressure lubrication characwheel.

8 teristics of the addition agents were evaluated by means of the Shell 4-Ball Extreme Pressure Tester and the Shell 4-Ball Wear Machine measuring the scar diameter at 40 kg. in millimeters.

The 4-ball Wear Tester was used to evaluate the ER and anti-wear characteristics of the lubricant additives of the present invention. It consists of an equilateral tetrahedron formed by four stainless steel balls, with the three lower balls immovably clamped in a ball holder. The fourth or upper ball is rotated about a vertical axis in contact with the three lower stationary balls under prescribed conditions of load, speed, temperature, and time in accordance with the following schedule.

Temp, F. l Time, Hrs. R.p.m. Load, kg.

1 1, 235 40 1 1,235 4 and 40 1 1, 235 4 and 40 1 1, 235 4 and 40 The contacting surfaces are immersed in the test fluid and the circular scars worn in the surface of the three stationary balls and measured by means of a low power microscope provide .a measurement of wear which is directly related to the load, speed, time of test, and character of the lubricant.

A modified cup and heater assembly is used to evaluate lubricants at 400 F. and higher temperatures and provisions have been provided which permit testing under an inert atmosphere. See The Study of Lubrication Using the Four-Ball Type Machine, R. G. Larsen, Lubrication Engineering, vol. 1, pp. 35-43, 59, August 1945.

The Four-Ball E. P. Tester consists of four balls of stainless steel arranged in the form of an equilateral tetrahedron. The basic elements are three lower balls held immovably in a clamp to form a cradle in which a fourth or upper ball is caused to rotate about a vertical axis under prescribed conditions of load and speed. The contacting surfaces on the f our-ball type apparatus are geometrically well-defined, thus providing obvious advantages in the study of wear and friction phenomena.

The points of contact are lubricated by the fluid under test, which is held in a cup surnounding the four-ball assembly. The weld point of the balls was determined by having them immersed in the test lubricant and gradually increasing the load on the balls by increment-s of 10 kgm. until the balls were welded together in a one minute test period.

Compositions comprising the polyphenyl ether fluids and the oxygenated organic tin compounds were also submitted to the Falex anti-weld test [see, e.g., the articles by V. A. Ryan in Lubrication Engineering, September 1946 and by S. Kyropoulos in Refiner Natural Gasoline Mfr., 18, 320-24 (1939)]. In this procedure, there was employed a Faville-LeVally Falex lubricant testing machine with heating element, 4,500 lb. pressure gage indicating bearing loads, calibrated, circular, toothed loader capable of providing wear estimates, and torque indicating gage. The machine is essentially a device in which a pin is rotated between two V-shaped bearing blocks which are immersed in an oil cup containing 55 ml. of the lubricant which is to be tested. The bearing blocks are inserted in self-aligning recesses in the short lever arms, or jaws, of the loading-applying mechanism. Pressure is applied through the loading mechanism which fits loosely over the bifurcated ends of the long lever arms. The ratchet wheel is turned up by hand until the loading mechanism takes hold, which is indicated by registration of applied load on its attached gage. Additional load is applied by engaging the load-applying arm with the ratchet The eccentric motion of the load-applying arm increases the application of load, one tooth at a time. The entire mechanism is free to swing about its axis, this tendency to turn being resisted by the syphon o erated 9 gage which registers torque in pound-inches. In the present tests, the machine was operated at 290 r.p.rn.

The antioxidant effect of the present oxygen-containing organic tin compounds on the polyphenyl ether fluids was determined by bubbling air through duplicate samples at 600 F. for a specified time (generally 24 or 48 hours) and then determining the viscosity (at 100 F.) and percent loss in weight of the treated sample. The percent change in viscosity (before and after oxidation) is taken as an index of anti-oxidant activity. Since the presence of metals also has been found to have an effect on the oxidation of polyphenyl ether fluids at high temperatures, in many instances the testing was also conducted in the presence of metals. In order to determine metal eflect, one set of duplicate samples of ether fluid and additive, copper, steel, aluminum and silver wires, whereas another duplicate set contained only 'the ether fluid and additive."

Example 1 A mixure of 5.5 g. (0.05 mole) of hydroquinone, 38.5 g. (0.1 mole) of triphenyltin chloride and 6.6 g. (0.1 mole) of 85% potassium hydroxide in benzene as diluent was refluxed in a flask equipped with a Dean-Stark trap under nitrogen for 5 hours. The resulting reaction mixture was filtered and the filtrate poured into petroleum ether to precipitate the substantially pure p-bis(triphenylstannoxy)- benzene, a white solid, M.P. 133-l35 C.

The compound was tested for use as antioxidant for a mixture of polyphenyl ethers consisting by weight of 65% of m-bis(m-phenoxyphenoxy)benzene of m- (m-phenoxyphenoxy) (p-phenoxyphenoxy) benzene 5 of m-bis(p-phenoxyphenoxy)benzene.

Test samples containing 1.0 g. of the p-bis(triphenylstannoxy)benzene and 100 g. of said mixture of ethers were prepared. Into one duplicate set of the samples there were immersed weighed pieces of iron, copper, aluminum and silver wire. Controls, i.e., samples containing no additive and with or without the same metals, were set up. The viscosity of all the test samples were determined at 100 F. The samples were heated to 600 F. and air was bubbled into the heated samples for 24 hours at a rate of 1 liter per hour. At the end of this time, the following results were obtained.

The sample of the ether mixture, alone, had a viscosity of 370.58 cs. before the test and a viscosity of 570.7 cs. after the test, i.e., there was a 54.07% change; but the viscosity of the ether mixture plus additive rose only from 373.29 to 409.69, i.e., there was only a 9.75% change. There was no change in the weight of ether mixture plus additive before and after the test, which fact shows 0.00 evaporation of the p-bis(triphenylstannoxy)benzene. In the wire tests, the viscosity rose from 370.58 to 515.1 (39.0%) in absence of the additive and from 373.29 to 406.05 (8.78%) in presence of the additive.

Example 2 A 20 g. sample of triphenyltin chloride was dissolved in 100 ml. of benzene, with stirring. To the stirred solution there was added 20 g. of sodium hydroxide dissolved in ml. of water. The mixture became turbid and stirring was continued for 2 hours. Separation of the layers and evaporation of the benzene solvent layer gave 17.0 g. of the substantially pure bis(triphenyltin) oxide, 21 white 10 soild, MP. l20124 C., analyzing 59.52% carbon and 4.54% hydrogen as against 60.38% and 4.22%, the re spective calculated values for C H Sn O.

Evaluation of said oxide as an antioxidant for polyphenyl ether fluid was as in Example 1 except that there was used in this case only 0.5 g. of the additive per g. of the mixed polyphenyl ethers and that air was passed into the test samples for a time of 48 hours in the presence of weighed pieces of copper, aluminum, silver and steel wires. Without the bis(triphenyltin) oxide, the viscosity of the polyphenyl ether mixture increased from 371 cs. to 614 cs. (61.9%) whereas in the presence of said oxide, it increased from 371 cs. to only 444 cs. (19.8%).

Example 3 A mixture of 34.3 g. (0.1 mole) of the diphenyltin dichloride and 20.0 g. (0.212 mole) of chloroacetic'a'cid was refluxed in toluene for 12 hours. The solvent was then removed under reduced pressure to obtain as residue the substantially pure diphenyltin bis(chloroacetate), a viscous, black oil.

Evaluation of the chloroacetate as an antioxidant for polyphenyl ether fluid was conducted as in Example 1, except that air was introduced for 48 hours in the absence of the metal wires. The viscosity of the mixture of ethers, containing no additive, rose from 371 cs. to 725 cs. (95.8% increase) as a result of the treatment, whereas in the presence of said chloroacetate it increased from 371 cs. to only 462 cs. (24.2%).

Example 4 Dibutyltin bis(2-ethylhexoate) (from dibutyltin dichloride and Z-ethylhexanoic acid) was evaluated as an antioxidant for polyphenyl ether fluid using the procedure described in Example 1. After the 24 hour period of air-flow, the viscosity of the ether fluid, alone, was 570.7 cs., whereas that of the ether fluid plus the Z-ethylhexoate was 464.38 cs.

Example 5 A mixture of 13.3 g. (0.05 mole) of diphenyltin dichloride and 16.3 g. (0.1 mole) of trichloroacetic acid was refluxed in toluene with stirring. The colorless reaction mixture turned almost black when the reflux temperature was reached. The mixture was cooled to room temperature and the solvent was removed under reduced pressure. There was thus obtained as residue the substantially pure diphenyltin bis(trichloroacetate), a green viscous oil.

The modification of anti-wear and extreme pressureresisting characteristics by the diphenyl bis(trichloroacetate) was determined for the mixture of polyphenyl ethers of Example 1 by the hereinbefore described testing procedures. At a concentration of 1 g. of the trichloroacetate per 100 g. of the mixture of ethers, the weld point was greater than 720 kg. as against kg., the weld point value for the mixture of ethers in the absence of an additive. The Falex test reading for the polyphenyl ether mixture plus trichloroacetate was greater than 4500, whereas that for the ether mixture only was 500.

Example 6 Bis(phenylthio)diphenyltin was tested as an antiwear and extreme pressure-resisting additive for the mixture of polyphenyl ethers described in Example 1. Evaluation was conducted as hereinbefore described, using 5 g. of the bis(phenylthio)diphenyltin per 100 g. of the mixture of ethers. There was thus obtained a weld point of 230 kg. and a scar diameter of 1.26 mm. at 40 kg. and 600 F., as compared to a weld point of 150 kg. and a scar diameter of 2.92 at 40 kg. and 600 F. for the mixture of polyphenyl ethers in the absence of an additive.

Example 7 Sodium carbonate (0.2 mole) was added to a benzene solution of 34.4 g. (0.1 mole) of diphenyltin dichloride 1 1 and 17 g. (0.1 mole) of p-xylene-a,ot-dithiol. The mixture was refluxed for 2 hours and filtered hot. Upon addition of petroleum ether to the filtrate, Stratification occurred. The upper layer of solvent was decanted, and the residue was Washed three times with ether and freed of solvent by evacuation in a vacuum desiccator to give the substantially pure viscous, polymeric product consisting of the repeating unit Evaluation of the above-obtained polymer as an antioxidant for polyphenyl ether fluid was conducted as in Example 1. At the end of the 24 hour test period in the absence of the metal wires there was a significant decrease in viscosity and no change in weight of the samples which contained said polymeric product.

Example 8 Bis(pentachlorophenylthio)dibutyltin was tested as an anti-wear and extreme pressure-resisting additive for the mixture of polyphenyl ethers of Example 1. Evaluation was conducted at a concentration of 2 g. of the tin compound per 100 g. of said mixture of ethers, employing the hereinbefore described procedures. There was thus obtained a weld point of 210 kg. as against 140 kg., the value obtained for the ether mixture in the absence of an additive, and a scar diameter of 1.31 mm. at 40 kg. and 400 F. and 1.29 mm. at the same pressure and 600 F. as against 2.12 mm. and 3.05 mm., the corresponding similarly obtained values for the mixture of polyphenyl ethers, alone.

Example 9 A mixture of 0.1 mole of diphenyltin oxide and 0.2 mole of pentachlorophenol was refluxed in toluene as diluent under a Dean-Stark trap until substantially 0.1 mole of Water had collected. The toluene was removed by distillation under partial vacuum and the residue was crystallized from dioxane-water to give the substantially pure bis[(pentachlorophenoxy)diphenyltin] oxide, white crystals, M.P. 157170 C. and having the structure in m This compound was tested as an anti-wear additive for the polyphenyl ether fluid of claim 1, employing the herein described four-ball testing procedure. There was thus obtained a scar diameter of 1.26 mm. at 40 kg. and 600 F. as compared to 2.92 mm., the value obtained for the mixture of polyphenyl ethers, alone, under the same testing conditions.

Although, in order to provide comparative data, there is employed as the polyphenyl ether component the same mixture of isomers, the organotin compounds wherein tin is linked to oxygen and/or sulfur possess adjuvant effect for the polyphenyl ether functional fluids, generally. Thus, instead of the mixture of by weight of m-bis- (m-phenoxyphenoxy)benzene, 30% by Weight of m- [(m-phenoxyphenoxy) (p-phenoxyphenoxy) ]benzene and 5% by weight of m-bis(p-phenoxyphenoxy)benzene, the polyphenyl ether component may be any one polyphenyl ether having from 4 to 7 benzene rings. For example, the bis(triphenylstannoxy)benzene of Example 1 or the bis(triphenylt in) oxide of Example 2 is a very good antioxidant fior any one of the three ethers of the polyphenyl ether mixture of Example 1, as well as for such other polyphenyl ethers as p-bis-[p-(m-phenoxyphenoxy)phenoxy] benzene, or m (m-phenoxyphenoxy) (o-phenoxyphenoxy)]benzerie, or in bis[m (p-phenoxyphenoxy) phenoxy1benzene, or mixtures thereof in any proportion. Lubricant mixtures of ethers are generally so constituted as to give simultaneously an optimum of thermal stability and lubricity at the temperatures to which they will be exposed in operation; but since the polyphenyl ethers, generally, are benefited by the organic tin-oxygen and/ or or tin-sulfur compounds With respect to increasing stability to oxygen and/ or film strength under conditions of high pressure at high temperatures, mixtures having varying proportions of the ethers are advantageously modified.

It is evident from the data presented above that addition of the organic tin-oxygen or tin-sulfur compound to the polyphenyl ethers results in one or more beneficial effects, i.e., there is brought about increased resistance to oxygen and/ or improvement in stability at operating conditions involving high pressure and temperature. At the same time, there may be generally decreased attack to metal so that anticorrosive effect i often demonstrated.

Since the quantity of the organic tin-oxygen or tinsulfur compound which is employed with the polyphenyl ether fluid will vary with adjuvant effect sought, with the nature of the polyphenyl ether and the nature of the individual adjuvant, it is evident that no rigid limits of adjuvant content can be set forth. For many purposes, particularly for antioxidant and anti-corrosive effects, very low quantities, say, quantities of as low as 0.01% by weight based on the weight of the polyphenyl ether fluid, are satisfactory. For other purposes, e.g., extreme pressure-resisting effect, higher concentrations will be more advantageous. Generally, polyphenyl ether compositions comprising from 0.01% to 10% by weight of the present additive demonstrate adjuvant effect. At concentrations of up to 10%, optimum improvement of the polyphenyl ethers is obtained with respect to antioxidant and lubricity and solubility of the additive in the polyphenyl ethers is generally realized. Determination of the optimum quantities is readily conducted by routine procedures, as will be apparent to those skilled in the art. Hence, the amount of the organotin-oxygen or organotin-sulfur compound to be used can best be expressed simply as an adjuvant amount. Variations or modifications of the compounds and quantities employed in the examples can be made to accommodate different requirements, so long as the additive belongs to the general class of organotin-oxygen or organotin-sulfur compounds hereinbefore defined and the polyphenyl ether fluid consists of polyphenyl ethers having from 4 to 7 benzene rings.

Although the present organotin-oxygen or organotinsulfur compounds confer a variety of beneficial properties to the polyphenyl ether fluids, they may be used with other additives, e.g., pour point depressants, viscosity index improvers, crystallization suppressants, dyes, etc.

Other modes of applying the principles of this invention may be employed instead of those specifically set forth above, changes being made as regards the details herein disclosed, provided the elements set forth in any of the following claims, or equivalents thereof may be employed.

13 What we claims is: 1. A functional fluid composition consisting essentially of a polyphenyl ether of the formula wherein n is a whole number from 2 to and from 0.1% to 10.0% by weight of the ether, of an organotin compound having a formula selected from the class consisting of where n is a number of from 2 to 3, m is a number of l to 2 and the total of m+n is 4, R is selected from the class consisting alkyl radicals of from 1 to 12 carbon atoms, benzenoid hydrocarbon radicals which are free of olefinic and acetylenic unsatura-tion and contain from 6 to 12 carbon atoms and such radicals carrying halogen substitution at the benzenoid nucleus, and aryloxyaryl radicals of from 12 to 24 carbon atoms; R is selected from the class consisting of R, paralfinic and haloparaffinic acyl radicals of from 2 to 12 carbon atoms, the radical wherein Z denote the necessary members to complete a saturated heterocyclic radical of from 6 to members, the radicals SnR and -aryleneO-S11R and X is a chalcogen element having an atomic weight of less than 33; and the formula where Y is selected from the class consisting of arylene radicals of from 6 to 12 carbon atoms, arylenealkylenearylene radicals and alkylenearylenealkylene radicals having from 1 to 4 carbon atoms in the alkylene radical and from 6 to 12 carbon atoms in the arylene radical, R and X are as above defined, and y is a number of 10 to 1000.

2. The composition defined in claim 1, further limited in that the organotin compound has the formula in which R is a saturated benzenoid hydrocarbon radical of from 6 to 12 carbon atoms.

3. The composition defined in claim 1, further limited in that the organotin compound has the formula wherein R is phenyl and R is a haloalkyl radical of from 1 to 12 carbon atoms.

4. The composition defined in claim 1, further defined in that the organotin compound has the formula it (alk) zSn(O U-allr);

wherein alk denotes an alkyl radical of from 1 to 12 carbon atoms.

5. The composition defined in claim 1, further defined in that the organotin compound has the formula wherein R is a saturated benzenoid hydrocarbon radical of from 6 to 12 carbon atoms.

6. The composition defined in claim 1, further limited in that the organotin compound has the formula X--SInX-alkylenearylenealkylenein which X is a chalcogen element having an atomic weight of less than 33, alkylene has 1 to 4 car-hon atoms and arylene has 6 to 12 carbon atoms, and R is a saturated benzenoid hydrocarbon atom of from 6 to 12 carbon atoms, the number of said repeating units in the polymer being from 10 to 1000.

7. The composition defined in claim 1, further limited in that the organotin compound has the formula wherein alk is an alkyl radical of from 1 to 12 carbon atoms and R is a saturated, halgen-substituted benzenoid hydrocarbon radical of from 6 to 12 carbon atoms.

8. The composition defined in claim 1, further limited in that the organotin compound has the formula in which R is a saturated halogen-substituted benzenoid hydrocarbon radical of from 6 to 12 carbon atoms and R is a saturated benzenoid hydrocarbon radical of from 6 to 12 carbon atoms.

9. The composition defined in claim 1, further limited in that the organotin compound is p-bis(triphenylstannoxy)benzene.

10. The composition defined in claim 1, further limited in that the organotin compound is bis(triphenyltin)oxide.

11. The composition defined in claim 1, further limited in that the organotin compound is diphenyltinbis(chloroacetate).

12. The composition defined in claim 1, further limited in that the organotin compound is dibutyltin bis(2-ethylheXoate).

13. The composition defined in claim 1, further limited in that the organotin compound is diphenyltin bis(trichloroacetate 14. The composition defined in claim 1, further limited in that the organotin compound is bis(phenylthio)diphenyltin.

15. The composition defined in claim 1, further limited in that the organotin compound is a polymer having the repeating unit the number of said repeating units in the polymer being from 10 to 1000.

16. The composition defined in claim 1, further limited in that the organotin compound is bis(pentachlorophenylthio)dibutyltin.

17. The composition defined in claim 1, further limited in that the organotin compound is bis(benzothiazolylthio)dibutyltin.

18. The composition defined in claim 1, further limited in that the organotin compound is bis[(pentachlorophenoxy)diphenyltin] oxide.

(References on following page) 1 5 1 6 References Cited by the Examiner FOREIGN PATENTS UNITED STATES PATENTS 851,651 10/ 1960 Great Britain.

2,181,914 12/ 1939 Rosen 25242-7 SAMUEL H. BLECH, Primary Examiner. 2,646,403 7/1953 Jenkins 25275 5 2,940,929 6/1960 Diamond 25233.6 JULIUS GREENWALD Exammer- 3,006,852 10/1961 Barnum et a1. 252-52 R. D. LOVERING, Assistant Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,290,247 December 6, 1966 Glenn R. Wilson et a1.

It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 2, lines 58 to 62, the formula should appear as shown below instead of as in the patent:

R Y-Xin-X column 3, line 25, for "(phenylthion)" read (phenylthio) column 4, line 29, for "Bis,triisobutyltin) oxide" read Bis[triisobutyltin) oxide line 68, for "bis[2-chloro3- iodophenoxy)" read bis[[2-chloro-3-iodophenoxy) column 6, line 1, 'for "tretramethylphenylene" read tetramethylphenylene column 7, line 25, for "media" read meta column 12, line 24, strike out "or"; column 13, line 29, for

column 14: line 23 for "halgen" read halogen Signed and sealed this 9th day of January 1968.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. EDWARD J. BRENNER Attesting Officer Commissioner of Patent 

1. A FUNCTIONAL FLUID COMPOSITION CONSISTING ESSENTIALLY OF A POLYPHENYL ETHER OF THE FORMULA (PHENYL-O-(PHENYLENE-O)N-)BENZENE WHEREIN N IS A WHOLE NUMBER FROM 2 TO 5 AND FROM 0.1% TO 10.0% BY WEIGHT OF THE ETHER, OF AN ORGANOTIN COMPOUND HAVING A FORMULA SELECTED FROM THE CLASS CONSISTING OF 